Run bundle after reissue:bump updates the version

[saturnflyer]

Summary

• Calls bundle after reissue:bump updates the version file, matching the behavior of the main reissue task
• Adds 3 regression tests verifying bundle is called (or not) after bump

Problem

When reissue:bump changes version.rb (e.g. from 2.1.14 to 3.0.0), the Gemfile.lock becomes stale because it still references the old gemspec version. The subsequent rake release then fails at release:guard_clean because there are uncommitted changes to the lockfile.

This was hit in SOFware/circulator's release workflow:

Version bumped (major) to 3.0.0
circulator 2.1.14 built to pkg/circulator-3.0.0.gem.
There are files that need to be committed first.
Tasks: TOP => release => release:guard_clean

The main reissue task already calls bundle after updating the version — reissue:bump was missing the same call.

Test plan

• 3 new tests added:
  • test_bump_calls_bundle_when_tag_matches_current_version — standard bump path
  • test_bump_calls_bundle_when_version_differs_from_tag — post-release bump path (the exact failure scenario)
  • test_bump_does_not_call_bundle_when_no_version_trailer — no unnecessary calls
• Full test suite passes (129 tests, 368 assertions)